Voice coil insertion jig, speaker producing method using the jig, and speaker produced by using the jig

ABSTRACT

A voice coil insertion jig is composed of hollow cylindrical insertion part  20   b  formed in the lower part of a base for inserting a magnetic circuit, a plurality of moving pieces formed thereon, and a central boss provided above the base. The moving pieces elastically contact with and hold the inserted voice coil. The central boss function as a knob.

TECHNICAL FIELD

The present invention relates to a voice coil insertion jig used inmanufacture of speakers incorporated in various acoustic appliances, amanufacturing method of speaker using this jig, and a speakermanufactured by using this jig.

BACKGROUND ART

A prior art is explained by referring to FIG. 3 to FIG. 5. FIG. 3 is asectional view of a speaker, FIG. 4 is a perspective exploded view of avoice coil assembling jig used when assembling the same, and FIG. 5 is asectional view explaining the assembling process of the voice coil.

A structure of a speaker is described in FIG. 3. Magnetic circuit 1 iscomposed of lower plate 1 a having center pole 1 b, magnet 1 c coupledon lower plate 1 a, and upper plate 1 d coupled on magnet 1 c. Magneticcircuit 1 has magnetic gap 1 e between upper plate 1 d and center pole 1b. Frame 2 is coupled to upper plate 1 d. Diaphragm 3 is coupled toframe 2 by way of edge 3 a formed on the outer circumference. Voice coil4 is composed of coil 4 a and bobbin 4 b. Coil 4 a is inserted inmagnetic gap 1 e, and the internal circumference of diaphragm 3 iscoupled to a specified position of bobbin 4 b. The outer circumferenceof damper 5 is coupled to frame 4, and its inner circumference iscoupled to bobbin 4 b. In this constitution, voice coil 4 is supportedmovably up and down.

In the manufacturing process of such speaker, what requires the highestprecision is the inserting process of voice coil 4 into magnetic gap 1e.

A conventional voice coil insertion jig disclosed in Japanese Laid-openUtility Model No. 57-160292 is explained by referring to FIG. 4 and FIG.5. The conventional voice coil insertion jig is composed of jig mainbody 11, gauge tube 12, slit 13, and spring 14.

Spring 14 is assembled into the inside of jig main body 11, andgenerates a force for opening slit 13. The insertion jig is insertedinto bobbin 4 b while closing slit 13, and after positioning, voice coil4 is fixed by the pressure of spring 14. Together with the jig, thevoice coil is inserted into center pole 1 b of magnetic circuit 1, thatis, voice coil 4 is inserted into magnetic gap 1 e. At this time,depending on the material thickness of gauge tube 12, the position ofvoice coil 4 in the radial direction is defined. In this state, frame 2is adhered and coupled to magnetic circuit 1. (Frame 2 may be firstadhered and coupled to magnetic circuit 1.) After adhering damper 5 anddiaphragm 3 to frame 2 and bobbin 4 b, the insertion jig is pulled outof the speaker. Finally, dust cap 6 is adhered and coupled to diaphragm3, and the speaker is manufactured.

Thus, in the speaker manufacturing process, the voice coil insertion jigis required to have a high precision for positioning voice coil 4.

As the appliance is reduced in size recently, a speaker of small sizeand high efficiency is demanded. For this purpose, magnetic gap 1 e isrequired to be much narrower.

DISCLOSURE OF THE INVENTION

It is hence an object of the invention to solve the above problem, andpresent a voice coil insertion jig for realizing a speaker of highperformance with a narrower magnetic gap by enhancing the positioningprecision of voice coil in the magnetic gap, a manufacturing method of aspeaker using the same, and a speaker manufactured by using the same.

The voice coil insertion jig of the invention comprises the following:

-   -   a base;    -   a hollow cylindrical insertion part provided integrally in the        lower part of the base;    -   a plurality of moving pieces provided integrally in the upper        part of the base, the outside diameter being formed the        plurality of moving pieces being larger than the outside        diameter of the insertion part; and    -   a central boss provided above the center of the base, being        apart from the moving pieces, the plurality of moving pieces        elastically contacting with and holding the voice coil.

A manufacturing method of a speaker of the invention uses the voice coilinsertion jig composed as shown above, and comprises the steps of:

-   -   a) deforming a plurality of moving pieces elastically to the        central boss side, and inserting into a voice coil;    -   b) restoring the elastic deformation, and holding the voice coil        in a voice coil insertion jig;    -   c) inserting the voice coil insertion jig holding the voice coil        into a magnetic gap forming a magnetic circuit;    -   d) adhering the inner circumference of a diaphragm to the voice        coil, and adhering the outer circumference of the diaphragm to a        frame; and    -   e) deforming the plurality of moving pieces elastically to the        central boss side, and extracting the voice coil insertion jig        from the magnetic gap.

The speaker of the invention is manufactured in this manufacturingmethod using the voice coil insertion jig composed as described above.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a top view of a preferred embodiment of voice coil insertionjig of the invention.

FIG. 1B is a sectional view of A-O-B side in FIG. 1A.

FIG. 1C is a bottom view of the same.

FIG. 2A is a top view of other preferred embodiment of voice coilinsertion jig of the invention.

FIG. 2B is a sectional view of A-O-B side in FIG. 2A.

FIG. 2C is a bottom view of the same.

FIG. 3 is a side sectional view of speaker.

FIG. 4 is a perspective exploded view of voice coil assembling jig usedin assembling of the same.

FIG. 5 is a sectional view explaining the assembling process of thevoice coil.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of voice coil insertion jig of the invention aredescribed below while referring to FIG. 1A to FIG. 2C and FIG. 3. Sameparts as in the prior art are identified with same reference numerals,and the explanation is omitted.

(Preferred Embodiment 1)

FIG. 1A is a top view of a preferred embodiment of voice coil insertionjig, FIG. 1B is a sectional view of A-O-B side in FIG. 1A, and FIG. 1Cis a bottom view of the same.

Voice coil insertion jig 20 is composed of base 20 a, hollow cylindricalinsertion part 20 b provided in its lower part, plurality of movingpieces 20 c, and central boss 20 d. Plurality of moving pieces 20 c areprovided integrally in the upper part of base 20 a, being apart fromeach other, and the outer circumference is formed as an arc of a nearlysame circumference. The diameter in the upper parts of plurality ofmoving pieces 20 c is constant, and the diameter is smaller in the lowerparts, that is, a slope is provided. Central boss 20 d disposed apartfrom moving pieces 20 c is formed so as to extend upward from the centerof base 20 a. The outer circumference is opposite to plurality of movingpieces 20 c across a specified gap.

Moving piece 20 c has horizontal slit 20 e at its lower outer side.Moving pieces 20 c formed integrally in base 20 a are separated byvertical slit 20 f.

Slit 20 f is formed for reducing the outside diameter formed by movingpieces 20 c when inserting voice coil insertion jig 20 into voice coil4, or when extracting voice coil insertion jig 20 from voice coil 4.Therefore, the width of slit 20 f is not particularly defined as far asmoving pieces 20 c can be inclined for inserting and extracting process(it is further preferred to set the slit width to such an extent thatmoving pieces 20 c may not be inclined over the limit of elasticity forthe sake of inserting and extracting process).

Diameter d1 of outer circumference of base 20 a and insertion part 20 b,and diameter d2 formed by upper parts of moving pieces 20 c in ordinarystate are in the relation of d2>d1. The diameter of outer circumferenceformed by the lowest end parts of the outer side of moving pieces 20 cis set nearly at d1, and this d1 is set to be equal to the innercircumference of voice coil 4. As clear from FIG. 1A, moving pieces 20 care polygonal (tetragonal in the preferred embodiment) at the inner wallside, and its the apex, vertical slit 20 f is formed as stated above.The slit width represents the interval of mutually opposing sides ofmoving pieces 20 c.

Central boss 20 d is formed longer than moving pieces 20 c, and it isused as a knob in the working process.

Magnetic gap 1 e between voice coil 4 and magnetic circuit 1 is assuredby the thickness of insertion part 20 b. (The outer circumference ofcenter pole 1 b of magnetic circuit 1 and the inner circumference ofinsertion part 20 b are nearly equal, and only a slight allowance forinsertion during assembling process is provided, and the intervalbetween the outer circumference of center pole 1 b and voice coil 4 isassured by the thickness of insertion part 20 b, and hence an intervalbetween upper plate 1 d and voice coil 4 is also assured.)

An assembling method of a speaker is explained.

By pushing moving pieces 20 c of voice coil insertion jig 20 to theinner side to deform within an elastic deforming range, voice coilinsertion jig 20 is inserted into voice coil 4. After inserting up to aspecified position, the inward pushing force applied to moving pieces 20c is released. As a result, moving pieces 20 c elastically contact withthe inner side of voice coil 4 in the restoring process. Thus, voicecoil 4 is held in voice coil insertion jig 20.

While holding voice coil 4, insertion part 20 b is fitted into centerpole 1 b of magnetic circuit 1 preliminarily adhered and coupled toframe 2, and inserted into magnetic gap 1 e.

In succession, damper 5 and diaphragm 3 are adhered to frame 2 and coilbobbin 4 b as shown in FIG. 3. Then, with moving pieces 20 c beingpushed to the central boss side, insertion jig 20 is pulled out.Finally, dust cap 6 is adhered to diaphragm 3.

In this manner, by using voice coil insertion jig 20 of the preferredembodiment, positioning and fixing of voice coil 4, and handling whenassembling the speaker can be done easily by using moving pieces 20 cand central boss 20 d, so that the working efficiency can be enhanced.

Further, since insertion part 20 b does not have slit 13 as in the priorart, but is a hollow tube, deformation of voice coil 4 can be prevented.

Moreover, magnetic gap 1 e depends only on the thickness of thisinsertion part 20 b, so that magnetic gap 1 e can be assured stably.Hence, magnetic gap 1 e can be narrowed, and the magnetic efficiency isenhanced and higher output is realized, while the magnetic circuit isreduced in size and the weight of the speaker can be also reduced.

In the preferred embodiment, a speaker having damper 5 is explained, butit can be similarly applied to a speaker without damper.

(Preferred Embodiment 2)

Other preferred embodiment of the invention is explained by referring toa top view of the other preferred embodiment of voice coil insertion jigin FIG. 2A, a sectional view of A-O-B side of FIG. 2A in FIG. 2B, and abottom view of the same in FIG. 2C. In the following explanation, sameparts as in preferred embodiment 1 are identified with same referencenumerals, and the explanation is omitted.

Only different points from preferred embodiment 1 are described below. Afirst different point is that center pin 20 g is provided in insertionpart 20 b. Center pin 20 g is formed downward in the center of base 20a. In the center of center pole 1 b, a hole (not shown) for insertingcenter pin 20 g is formed. In the manufacturing process, by insertingcenter pin 20 g into the hole formed in center pole 1 b, voice coil 4 ispositioned.

As a result, same as in preferred embodiment 1, it is not required toposition voice coil 4 by defining the outer circumference of center pole1 b same as the diameter of inner circumference of insertion part 20 bas much as possible, and by inserting center pin 20 g, it is easier toposition voice coil 4 than in preferred embodiment 1, and also voicecoil 4 can be positioned without depending on the diameter of centerpole 1 b, so that the jig can be managed easily without preparinginsertion jig 20 for the portion of difference in outside diameter ofcenter pole 1 b.

INDUSTRIAL APPLICABILITY

As described herein, the invention presents a voice coil insertion jigcapable of assembling a speaker at excellent working efficiency and highprecision without deforming the voice coil, a manufacturing method usingthe same, and a speaker manufactured by this method.

1. A voice coil insertion jig comprising: a base; a hollow cylindricalinsertion part provided integrally in the lower part of the base; aplurality of moving pieces provided integrally in the upper part of thebase, the outside diameter being formed the plurality of moving piecesbeing larger than the outside diameter of the insertion part; and acentral boss provided above the center of the base, being apart from themoving pieces, wherein the plurality of moving pieces elasticallycontact with and hold the voice coil.
 2. The voice coil insertion jig ofclaim 1, wherein the plurality of moving pieces contact adjacently toeach other by way of a slit formed in a direction perpendicular to thebase, and each one of the plurality of moving pieces has a horizontalslit on the outer circumference of the base side.
 3. The voice coilinsertion jig of claim 1, further comprising: a center pin formed in thelower center of the base, projecting downward.
 4. The voice coilinsertion jig of claim 1, wherein the central boss is longer than theplurality of moving pieces.
 5. A manufacturing method of a speaker usingthe voice coil insertion jig as set forth in claim 1 comprising thesteps of: a) deforming a plurality of moving pieces elastically to thecentral boss side, and inserting into a voice coil; b) restoring theelastic deformation, and holding the voice coil in a voice coilinsertion jig; c) inserting the voice coil insertion jig holding thevoice coil into a magnetic gap forming a magnetic circuit; d) adheringthe inner circumference of a diaphragm to the voice coil, and adheringthe outer circumference of the diaphragm to a frame; and e) deformingthe plurality of moving pieces elastically to the central boss side, andextracting the voice coil insertion jig from the magnetic gap.
 6. Aspeaker manufactured in the manufacturing method as set forth in claim5.
 7. A voice coil insertion jig comprising: a base; an insertion partfor fitting a center pole of a hollow cylindrical magnetic circuitprovided integrally in the lower part of the base; a plurality of movingpieces provided integrally in the upper part of the base, the outsidediameter being formed the plurality of moving pieces being larger thanthe outside diameter of the insertion part; and a central boss providedabove the center of the base, being apart from the moving pieces,wherein the plurality of moving pieces elastically contact with and holdthe voice coil.
 8. The voice coil insertion jig of claim 7, wherein theplurality of moving pieces contact adjacently to each other by way of aslit formed in a direction perpendicular to the base, and each one ofthe plurality of moving pieces has a horizontal slit on the outercircumference of the base side.
 9. The voice coil insertion jig of claim7, wherein the central boss is longer than the plurality of movingpieces.
 10. A manufacturing method of a speaker using the voice coilinsertion jig as set forth in claim 7 comprising the steps of: a)deforming a plurality of moving pieces elastically to the central bossside, and inserting into a voice coil; b) restoring the elasticdeformation, and holding the voice coil in a voice coil insertion jig;c) fitting an insertion part of the voice coil insertion jig holding thevoice coil into a center pole of a magnetic circuit, and placing thisinsertion part into a magnetic gap; d) adhering the inner circumferenceof a diaphragm to the voice coil, and adhering the outer circumferenceof the diaphragm to a frame; and e) deforming the plurality of movingpieces elastically to the central boss side, and extracting the voicecoil insertion jig from the magnetic gap.
 11. A speaker manufactured inthe manufacturing method as set forth in claim
 10. 12. A voice coilinsertion jig comprising: a base; a center pin formed in the lowercenter of the base, projecting downward; a hollow cylindrical insertionpart provided integrally in the lower part of the base; a plurality ofmoving pieces provided integrally in the upper part of the base, theoutside diameter being formed the plurality of moving pieces beinglarger than the outside diameter of the insertion part; and a bossforming the center pin formed in the lower center of the base,projecting downward, provided above the center of the base, being apartfrom the moving pieces, wherein the plurality of moving pieceselastically contact with and hold the voice coil.
 13. The voice coilinsertion jig of claim 12, wherein the plurality of moving piecescontact adjacently to each other by way of a slit formed in a directionperpendicular to the base, and each one of the plurality of movingpieces has a horizontal slit on the outer circumference of the baseside.
 14. The voice coil insertion jig of claim 12, wherein the centralboss is longer than the plurality of moving pieces.
 15. A manufacturingmethod of a speaker using the voice coil insertion jig as set forth inclaim 12 comprising the steps of: a) deforming a plurality of movingpieces elastically to the central boss side, and inserting into a voicecoil; b) restoring the elastic deformation, and holding the voice coilin a voice coil insertion jig; c) inserting the voice coil insertion jigholding the voice coil into a hole having a center pin provided in acenter pole of a magnetic circuit, and inserting the voice coilinsertion jig into a magnetic gap formed by the magnetic circuit; d)adhering the inner circumference of a diaphragm to the voice coil, andadhering the outer circumference of the diaphragm to a frame; and e)deforming the plurality of moving pieces elastically to the central bossside, and extracting the voice coil insertion jig from the magnetic gap.16. A speaker manufactured in the manufacturing method as set forth inclaim 15.